Steam-pressure gage



E. H. ASHCROFT.

Steam Pressure Gage.

No. 45,685. Patented Jan. 3.1865.

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UNITED STATES PATENT OFFICE.

EDWARD H. ASHCROFT, OF LYNN, MASSACHUSETTS.

STEAM-PRESSU RE GAGE.

Specification forming part of Letters Patent No. 45,685, dated January3, 1865.

To all whom it may concern.-

Beitknown that I, EDWARD H. Asncuorr, of Lynn, in the county of Essexand State of lltassachusetts, have invented an Improved CorrugatedDisk-Sprin g and I do hereby declare that the following, taken inconnection with the drawings which accompany and form part of thisspecification, is a description of my invention sufficient to enablethose skilled in the art to practice it.

My invention relates to the construction of disk or plate springs, suchas are used in certain We l-hnown steam gages. These springs are formedin a lathe by chucking a metallic disk, generally of sheet brass,against the face of a chuck-plate having concentric undulations on itsface, to the surface of which the disk, as it rotates, is bent bypressure of a burnisliingtool, having not only an advance oradvanceand-retreat movement, but a lateral or radial movement, so as tocause the rear face of the rotating disk to conform to the face of thechuck-plate by the pressure and radial move- 111 nt of the tool. Theaction of the tool not only produces this change of form, but liardensand solidifies the face against which it operates, so as to give atemper to the spring. This operation, however, hardens only one face ofthe disk; and my invention consists in a corrugated disk-spring havingboth faces hardened or tempered.

Figure l is a representation of one of these springs, and Fig. 2 acentral cross-section of the same.

The operation of producing the improved 1' which the spring is to beformed having been chucked in the lathe on a chuck'plate, the face ofwhich is corrugated radially in the form desired for the spring,longitudinal and lateral movement is then imparted to theburnishingtool, producing the concentric concavities and convexities inthe disk, conforming to the concavities and con vexities in the faceofthe chuckplate, the action of the tool in effecting this change ofform and this and subsequent pressure of the tool producing the desiredhardening or tempering of the disk-surface. After one face of the diskis thus finished the disk is removed from the chuck-plate, and anotherchuck-plate having been substituted for the one first used, the face ofwhich corresponds to the hardened face produced on the disk, the disk isagain bolted to this chuck-plate, with the other face presented for theoperation of the burnishingtool, such operation hardening and temperingthis face similarly to the other.

It will be readily understood that the spring, thus finished,by theapplication of the hardening process to both faces increases theintegrity of the spring, rendering it much more serviceable than thespring tempered upon only one face.

1 claim- A corrugated disk-spring hardened or tempered, substantially asset forth.

In witness whereof I have hereunto set my hand this 6th day of October,A. l). 1864.

E. H. ASHCROFT. Witnesses J. B. URosBY, l1. GOULD.

